The invention concerns an ultrasonic welding machine having a tool in the form of a sonotrode, a backplate electrode, or a side element with four working surfaces that delimits a compression chamber, wherein these surfaces can be selectively aligned on the material to be welded, for example, flexible wires or pipes made of metal, and extend across at least one end face of the tool passed through by the longitudinal axis of the tool, wherein the end face rests on an element such as a mounting, booster, or converter, via which the tool is connected to the ultrasonic welding machine, and wherein the tool is rotated around the longitudinal axis in order to align one of the working surfaces on the material in a desired position with respect to the element. The invention concerns also a tool of an ultrasonic welding machine in the form of a sonotrode having two mutually opposite end faces, as well as at least one surface running between the end faces and perpendicular or approximately perpendicular to the end faces, which is a working surface when aligned on a backplate electrode.
From EP-A-0 083 707 an ultrasonic welding machine with tools is known, which comprises a sonotrode with four working surfaces, and an anvil with four working surfaces. Thereby, the sonotrode as well as also the anvil can be rotated around its, or their respective longitudinal axis in order to make possible an alignment of the working surfaces on compression chambers having different cross sections.
From EP-A-0 286 975, as well as also from U.S. Pat. No. 4,782,990 ultrasonic welding machines are known in which the backplate electrode can be shifted by 180° in order to make available different working surfaces, which delimit a compression chamber.
An ultrasonic welding machine according to EP-B-0 723 713 comprises a sonotrode that generates ultrasonic vibrations, of which one section is a first boundary surface serving as working surface of a compression chamber, which is adjustable in height and width, preferably rectangular in cross section, and open on the face side. The remaining boundary and working surfaces are formed by sections of a multi-piece backplate electrode as well as a side shifting device.
From EP-B-0 761 370 an ultrasonic welding machine is known in which each of the mutually opposite end faces of the sonotrode is connected to a booster. The length of the sonotrode corresponds to the wavelength λ of the ultrasonic waves. In the antinode of the sonotrode, which has a cylindrical shape, several projections forming working surfaces are provided. In order to align each of the working surfaces on a backplate electrode (also called anvil), the sonotrode must be rotated around its longitudinal axis.
In WO-A-02/43915 an ultrasonic welding machine is described in which a side shifting device delimits a compression chamber. The side shifting device has several working surfaces. The side shifting device can be rotated and/or turned in order to align each one of the working surfaces on a compression chamber.